From what I understand, there is nothing in the law that specifies that you have to be religiously opposed to all vaccines. In fact, some of the letters that I read while writing mine was indicating which vaccines they were opposed to due to what specific reasons (embryos, etc.).
I stressed about it too at first, but now its really not a big deal. My younger DD is 2 years old and a few months, she's only had 5 shots. We switched recently from the daycare center to a private home daycare and they don't care at all.